Unraveling Health Risk and Speciation of Arsenic from Groundwater in Rural Areas of Punjab, Pakistan

This study determined the total and speciated arsenic ( As) concentrations and other health- related water quality parameters for unraveling the health risk of As from drinking water to humans. Groundwater samples ( n = 62) were collected from three previously unexplored rural areas ( Chichawatni, Vehari, Rahim Yar Khan) of Punjab in Pakistan. The mean and median As concentrations in groundwater were 37.9 and 12.7 mu g center dot L-1 ( range = 1.5- 201 mu g center dot L (-1)). Fifty three percent groundwater samples showed higher As value than WHO safe limit of 10 mu g center dot L-1. Speciation of As in groundwater samples ( n = 13) showed the presence of inorganic As only; arsenite ( As( III)) constituted 13%- 67% of total As and arsenate ( As( V)) ranged from 33% to 100%. For As health risk assessment, the hazard quotient and cancer risk values were 11- 18 and 46- 600 times higher than the recommended values of US- EPA ( i. e., 1.00 and 10- 6, respectively). In addition to As, various water quality parameters ( e. g., electrical conductivity, Na, Ca, Cl-, NO3-, SO42-, Fe, Mn, Pb) also enhanced the health risk. The results show that consumption of As- contaminated groundwater poses an emerging health threat to the communities in the study area, and hence needs urgent remedial and management measures.